Kawasaki Ninja Forum banner
1 - 20 of 43 Posts

·
Registered
Joined
·
331 Posts
Discussion Starter · #1 ·
Big tires on our Ninja had been a quest on many topics.But just put a wider tire on the rear 3.5" mini rim is not a total solution.Accept for the balloon look we gain very little,if any,out of that big tire.The side walls are squeesed so much that the shoulder will never be able or ever touch the road.Grip will never be obtimised.
To make most out of a wider tires we must be able to put the whole rubber on the ground.To do this we need wider rim.The biggest tire suitable for a 3.5"rim is size 140 but std it should be 130.
To put on a prefered 150 tires we need 4.5" rim.The maximun safe size on 4.5" rim is a 160 tire.
I've been thinking of this since 1st day I got my 250.Untill lately when Kawasaki Thailand released there new er6n
(in US they call it Ninja 650R) that I see the way to upgrade my rear tire.After fumbling around with planning measuring and calculating for a month I have myself a go.I ordered a brand new er6n rim,new sprocket coupling,rear break disc and one socket bolt(why one-see text).
To put on a wider rim I needed to do some basic modification.
Here's how.

Std Ninja Hub damper



Std er6n Hub damper



NJ's coupling.The bolts are wider apart then er's




er's coupling



Comparison:Top er's,below Ninja's




Remove the bearings out of hub.The bearing on er is bigger # 6204.The ID is 20 mm compare to 17 mm on Ninja.As well as the collar.The ID is 20mm.These holes must be made smaller by inserting a bushing reduceing the ID to 17mm so that the Ninja's original axle can be used.It's a 17mm diameter.Other option is to change the bearing to # 6303 which has The OD=er's but ID=NJ's.But why spend more.A small bushing cost next to nothing.


Knock out the bearings.Carefull not to damage the seals




er's bearing on NJ's axle.Look how loose it is.



Next on the list is the break caliper holder,hub sleeve and the two collars.They must be shave off a little.The er's hub is 15mm wider than NJ's.So reducing the total width by 15mm is essencial.


This holder is way to thick.Shave!




To make long story short!

These are all the parts that need modifying.
The sprocket will also go under butcher's knive.





The dismantle and measuring took me a couple of hours.Then took the parts to the milling shop before noon.Believe it or not
I got everything back same day before dark.Cost me 2000 Baht (57$).
I wrote somewhere if it takes more then 4 hrs I'll go banana.OK,must admit,this time no banana.
Assembly was done next day.
Lets go on.


Finished parts back from shop.Look carefully.Can you see the bushings?They were locked in with permanent locktite



The sprocket,raw.The original holes was filled using epoxi steel then painted




Filled and painted




Assembling was kind of streight forward.Backward of dismantling.The er original seals were used as they do fit NJ's collar.

Bearing back in




Seal on.Put some grease on it's lips.


Remember the one bolt I mentioned earlier?As the disc on er rim uses 4 instead of 3 on NJ.I reuse those 3 bolts +the one I bought.




Sprocket in place.See any trace? yeah,FI use only 43 teeth.



Check left,check right.Nice fit.







The most difficult mod on this project is the caliper holder.I shaved it off 11mm.In this form it's imposible to put it back on.On the right swing arm there's a stopper which take the rotating force of the holder.I handmade the next mod myself.It might look a little scary but when we break hard the rotating force will push the holder on to the stopper.No problem here.On the other hand if you CAN drive backward(?) fast and break hard the lower part of the holder might break.But who can do that.


Seen here is the holder and the stopper.How can this fit?No way.



I hand sew the original grove completely off and filled it smooth.




Cut holder and the stopper.Good fit.






Now put everything back on conventional way,start engine,put it in gear and rev.
Look terrible without tire but who's looking.





The tire I use is Battlax BT-39(same in the front)size 150/70-17.It fits perfect.Leaving plenty of space between tire and chain.On right side the gap to swing arm is not much only around 5 mil.So 150size is the widest for this mod.


Lots of clearance to chain guard...........




..........but not much to right swingarm.Enough though.




Finished product.A work of two days and brain storn for a month.Not a single mistake in calculation.




What would a write up be without a road test.
Ok,just a small one.
I headed out to my....em....personal race track?It's just a small junction next to my house.No traffic.
After ridding over some dust and sand for awhile(another way to get rid of the oilly stuff on the tire quick)it's time to test the handling.
I must say the bike behave differently.It wants to stand up(streighten up)more then before.I must hang out more into the curve to compensate.I have been using the same tire in smaller size(130) and tried out on this junction many times before but the gain in grip on this new bigger tire was .......Oh wow!And the good look of it wow wow.Used up the rubber all the way to the shoulder. wow wow wow!
I was in such fun that my wife who's takking the shots must ask me to stop.She's getting dizy just by watching me go round and round for half an hour.


Yeah,that's me haveing fun.I know I know.............safty gear!
If I just open up my knees it will scab the road but you know bare knee and cement it's a no go.






The tire was used up to the shoukder





Summery:I used to say somewhere before that I like do things myself.And this one is one of the many project I've done.Man,I love what I'm doing.
I cost for all of this was around 16000 Baht(431 US$).In my oppenion the money was well spent.
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #3 ·
Felix said:
Wow! Nice part one! cant wait for next part!

Eric, I was wondering, apart from look, is their any other reason to do this?

Felix
Try to finish everything on one page.So no part one or part two.I'm not hunting for points.
The real reason behind all this is the perfomance.You see I love to go on long trips.Especially mountain roads with lots of curves.The 130 tires are not bad but have there limits.When I go deep into a curve it feels kind of mushy.The rear tire feels like it's about to let go.The front tire grips ok.So putting more rubber on the road should increase grip and seams it does.The BT-39 I use is a sport tourer.Been happy with them since my last bike.Naturly a BT-090 would be much better but it will wear off much quicker.
 

·
The Man, The Mystery, The Itch.
Joined
·
4,853 Posts
Cant wait to see the end result and yeah this topic has come up hundreds of times. Nice part 1!

I was thinking when I get mine that I'd get a bigger back tire, been awhile since I've been on a bike. Plus the streets out here have alot of wet oil even on the sides because of the population, more tread would probably help that right? Or just be more rubber for the oil to catch?
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #5 ·
virtualmatrix258 said:
Cant wait to see the end result and yeah this topic has come up hundreds of times. Nice part 1!

I was thinking when I get mine that I'd get a bigger back tire, been awhile since I've been on a bike. Plus the streets out here have alot of wet oil even on the sides because of the population, more tread would probably help that right? Or just be more rubber for the oil to catch?
Oil and rubber never were good friends no matter what size.If you want bigger tires on your OME rims don't go over 140.It's useless.Spend $s for nothing.And you must be a damn good driver to make good use of the larger 140 rubber.
 

·
Registered
Joined
·
133 Posts
That looks amazing. I wish I had the time and money for this as well. Do ypu think they will eventually start making aftermarket rims (that are wider than stock) in the future for the new 250?
 

·
Registered
Joined
·
71 Posts
xthrice89 said:
That looks amazing. I wish I had the time and money for this as well. Do ypu think they will eventually start making aftermarket rims (that are wider than stock) in the future for the new 250?
I bet they will. there is enough demand out there for a bigger tire so i'm sure someone will make one. anyone know if they made a wider rim for pre 08 250's?
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #11 ·
xthrice89 said:
That looks amazing. I wish I had the time and money for this as well. Do ypu think they will eventually start making aftermarket rims (that are wider than stock) in the future for the new 250?
There MIGHT be some changes in the future.I don't know for sure.I have an appointment with Kawasaki Thailand Technical and Development Department in a couple of days.They can't believe it can be done.Even with the pic I E-Mailed them.They want to see it with there own eyes.Kawasaki actually used to use wider rim on there Balius and it's a perfect replacement,w/o mod,for the 250.Just wait and see.
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #13 ·
felix have they open up your engine?What did they say what caurses the failure?Or do you still have to wait another two month?
If you can e-mail me some pic of the bearing I could ask them.I will again visit the factory next Saturday.But I need something solid to show them.
 

·
Registered
Joined
·
2,012 Posts
eric... as to the mod u did on ur bike... my understanding is that you replace the back rim for a wider one. to fit a 150/70/17 right? why not replace the swing arm and fit a back wheel like the 6r? by the way thanks for the detail pics.
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #16 ·
Hi-tech,I didn't make very clear about the size of the tire that can be use in this project.

Summery:In 70 serie the biggest tire that can be use w/o scrubling is 140/70-17.
On 60 serie the biggest tire that can be use w/o scrubling is 150/60-17.(show pic at end)
But I highly recommen 150/60-17.Although the 140/70 and 150/60 share the same width when installed on wheel the 150/60 does give more lean ankle when cornering.The tire face of the 140 is not very round and will use up the useable face very quick.Means the deeper you lean the less rubber on road.Not good.

150/60-17 round shoulder=more lean ankle.


140/70-17 not so round face use up shoulder very quick.Limited lean ankle.


You mean the ZX6R?

As far as I know the 6R uses 5.5"wheel.Way too wide for our little Ninja.
 

·
Registered
Joined
·
2,012 Posts
Thanks for the info. Yeah. I was thinking of the replacement of the swing arm along with the wheel. From a r6 to the 250 ninja. Thanks for clearing up the size of the tire too.
 

·
Registered
Joined
·
2,012 Posts
That's pretty cool. Hey what is that round silver look like a piston with the letters VSS ? Right above the tire hugger.
 

·
Registered
Joined
·
331 Posts
Discussion Starter · #20 ·
YSS shock upsorber's subtank.Actually I change the whole set.This set is there newest release.So the webside is not yet up to date.The system is very promissing.Very comfortably soft for your back end but yet no wobbling when riding hard.Can adjust preload,bound and rebound to suit your style.Been using there product since my last bike.

http://www.yss.co.th/index.php

 
1 - 20 of 43 Posts
Top